# Snapshots

Snapshots is the billing unit of the builds in Widgetbook Cloud. A snapshot is a [addon configuration](/cloud/snapshots/multi-snapshot#multi-snapshot-for-addons) and [knob configuration](/cloud/snapshots/multi-snapshot#multi-snapshot-for-knobs) for a use-case inside a build. For example:

- A `Button` use-case can have a "dark" and a "light" configuration when using the [Theme addon](/addons/theme-addon).
- A `Button` use-case can have a "long text" and "short text" configuration when using the [string knob](/knobs/string).

In short, the snapshots is a **matrix** between addons configs and knobs configs for each use-case in a build.

| <Image src="/assets/cloud/snapshots/button-dark-short-text.png" zoom caption="Dark x Short Text"  /> | <Image src="/assets/cloud/snapshots/button-light-short-text.png" zoom caption="Light x Short Text" /> |
| ---------------------------------------------------------------------------------------------------- | ----------------------------------------------------------------------------------------------------- |
| <Image src="/assets/cloud/snapshots/button-dark-long-text.png" zoom caption="Dark x Long Text" />    | <Image src="/assets/cloud/snapshots/button-light-long-text.png" zoom caption="Light x Long Text" />   |

## Default Configuration

When you create a build, Widgetbook Cloud will automatically create a default configuration for each use-case. This configuration is the one that is shown when the use-case is first opened in Widgetbook. If you want to add more configurations, you can do so by using the [Multi Snapshot feature](/cloud/snapshots/multi-snapshot).

## How are snapshots counted?

To estimate your snapshots count per build, you can use the following formula:

```
Snapshots = Knobs configs * Addons configs
```

For example, if your build has:

- 3 use-cases:

  1. `Button` - 2 knobs configs (`short text` and `long text`)
  2. `Card` - 0 knob config _(default configuration is counted as 1)_
  3. `Avatar` - 1 knob config (`no image`)

- 2 addons configs:

  1. `Dark German` - Dark theme with German Locale
  2. `Light English` - Light theme with English Locale

This means that the number of snapshots per build will be as follows:

```
Knobs configs = 2 (Button) + 1 (Card) + 1 (Avatar) = 4
Addons configs = 2 (Dark German and Light English)
Snapshots = 4 * 2 = 8
```

## Exclude Use-cases

If you have some use-cases that you don't want Widgetbook Cloud to process the snapshots for, you can exclude them as follows:

```dart
@UseCase(
  name: 'Default',
  type: UnstableWidget,
  cloudExclude: true // [!code highlight]
)
Widget buildUseCase(BuildContext context) { ... }
```
